Cart Shopping Cart My Store Account Orders Downloads Shopping Cart “9. Aircraft Balancing and Center of Gravity Control” has been added to your cart. Continue Shopping Remove item Thumbnail image Product Price Quantity Subtotal × 4. The Weight Engineer and the Flutter Problem $20.00 4. The Weight Engineer and the Flutter Problem quantity $20.00 × 23. The Value of a Pound $20.00 23. The Value of a Pound quantity $20.00 × 9. Aircraft Balancing and Center of Gravity Control $20.00 9. Aircraft Balancing and Center of Gravity Control quantity $20.00 Coupon: Apply coupon Update cart Available coupons (Click to apply). Cart totals Subtotal $60.00 Tax $0.00 Total $60.00 Proceed to checkout